Pretreatment Of Landfill Leachate By Ammonia Stripping

Abstract

Ammonia stripping from landfill leachate has been investigated. The main objectives were to enhance biodegradability and to overcome ammonia toxicity to further biological treatment steps. The stripping process was carried out at various pH values ranging from 8.5 to 11. To investigate the impact of initial ammonia concentration on the stripping process, raw as well as diluted leachate (1 leachate: 1 water) were used for the present study. The efficiency of the treatment process was monitored by chemical analyses and Vibrio fischeri toxicity test. The chemical analyses covered ammonia nitrogen (NH4–N) and organic pollutants (COD and BOD5).The improvement in biodegradability was measured by the BOD/COD ratio. The highest removal efficiency of ammonia nitrogen (NH4-N) was obtained at pH value of 11 after air stripping for 24 hr. Average removal values were 94.5% for raw leachate and 96.9% for diluted leachate. The biodegradability, as expressed by the BOD/COD ratio, increased from 0.34 for raw leachate to 0.38 after ammonia stripping for 24 hr at pH values of 10 and 11. Kinetics of the rate of reaction for raw and diluted leachate indicated the preference of the use of raw leachate.